The Prohibition era in America, which lasted for well over a decade and—inconceivable as it might be today—effectively banned the sale and production of booze in the United States, ended with the ratification of the 21st Amendment on Dec. 5, 1933.

These images might look, at first glance, like standard shots of a horse race — clouds of dust billow as hooves tear the ground, riders hold crops high as they compete for the top spot. But look a little closer: These jockeys are kids.

Indonesian photographer Romi Perbawa has spent four years documenting the child racers of Sumbawa Island in the West Nusa Tenggara province of Indonesia. Held at the end of the rice-harvesting season, which usually falls between April and July, these races often involve children as young as 5 years old, with the horses they ride regularly racing at incredibly high speeds.

Shockingly, safety gear — such as harnesses and saddles — is rarely used, despite the risk of injury, and the local government considers the races an important part of island culture. Here, horseback racing is a tradition that is passed on from generation to generation.

Horses, after all, form an important part of island life and are crucial for transport. Almost all families in the area have their own horse and youngsters learn to ride at a very young age. The local government provides a large area on the slopes of Mount Tambora in which families keep their horses. Indeed, families do not have to pay rent on the land and there is no tax levied on the ownership of horses.

“These child riders are considered heroes,” Perbawa says, “but in many ways they are also losing out.” Why? “The children are paid only a small fee of around 20,000 to 50,000 Indonesian rupiah, the equivalent of about $5, for each race.” Spectators stand to make more money than the racers, in fact, if they put money on a winner. This betting, though, is not regulated by Indonesian authorities.

Stormy Riders, Perbawa’s book on the subject will be released May 30, 2014, in Indonesia, and his solo exhibition on the subject will be shown ANTARA Gallery of Photojournalism in Jakarta.

But Perawba isn’t giving up on the thrill of the race just yet: he intends to make this a generational project. “I want to document the lives of these kids until they mature,” he adds, “until they themselves have children who will be their successors.”